USB: change dev_WARN to dev_err triggerable from user space
Quoted 5 lines · Oliver Neukum
Quoted 4 lines · Johan Hovold
Quoted 2 lines · Oliver Neukum
For those people who run with
panic_on_warnaWARN()triggered from user space is a DOS. It is worth returning todev_err()
Quoted 7 lines
Quoted 4 lines
I think this should be
dev_warn()unless you want to bring back the returning of errors on these conditions as well (i.e. as was the case prior to0cb54a3e47cb("USB: debugging code shouldn't alter control flow")).Should I? A warning in syslog is pretty hardcore, so I have no idea whether
dev_warn()is enough.
Perhaps there are two sides to this. If something really should not be happening and needs to be addressed (i.e. it's a driver bug) that dev_WARN is warranted. If user space can be pass in bogus flags that gets propagated to USB core, perhaps those need to be sanitised sooner (in the vain of "don't trust anything coming from user space").
In general though, I believe dev_warn() is more appropriate for cases where something odd is happening, but we try to recover and proceed anyway (e.g. by sanitising the flags without bailing out as is the case here) instead of aborting.
Johan